Targeted Tuberculin Testing and Interpreting Tuberculin Skin Results

This information sheet discusses targeted tuberculin testing focusing on the groups at highest risk for latent TB infection (LTBI). It advises that testing should be given to those at highest risk for developing TB, and once TB disease has been ruled out, then it should be offered to those who would benefit from LTBI treatment. It also explains the steps that should be taken to ensure completion of the regimen. The information sheet groups persons at risk for developing TB disease into two categories: those who have been recently infected, and those with clinical conditions that increase the risk of progression from LTBI to TB disease. It also lists criteria for classifying positive TST reactions and clarifies questions about the interpretation of TST results in persons who had received bacille Calmette-Guerin (BCG) vaccine, persons with HIV infection, and recent contacts of a person with active TB.